This study was carried out to compare farrowing rate and litter traits for European and American lines with boar sperm frozen in straws. Farrowing rate, litter size and mean pig weght at birth and 21 days were investigated. A total of 36 gilts Landrace, Large white and Duroc were investigated at the Chungnam Provincial Animal Breeding Station. We obtained higher farrowing rate and litter traits for European line boars compared to American line boars.

It is largely divided into two kinds in freezing phenomenon of the tunnel. Waterproof membrane damage inside the tunnel construction joints leaked into groundwater leak occurs in the icicle and despite the absence of damage to the waterproofing membrane, waterproofing membrane from the back of the ground water is frozen freeze by interfering with smooth drainage this phenomenon is enlarged and local pressure tunnel ceiling, a crack occurred near the side wall is generated